General poisoning notes:

Wild calla (Calla
palustris) is a native plant that grows in swamps and marshes through much
of Canada. Calcium oxalates occur, which can cause severe irritation of the
mouth and throat. No cases of livestock poisoning are found in the literature,
but the potential for poisoning is present. Humans are also at risk from this
plant (Kingsbury 1964, Lampe and McCann 1985).

Notes on Poisonous plant
parts:

All parts of the
plant contain calcium oxalate crystals, which can cause irritation of the mouth
and throat (Lampe and McCann 1985).

Toxic parts:

Leaves, rhizome, stems,
roots.

Toxic plant chemicals:

Oxalate.

Animals/Human Poisoning:

Note: When an
animal is listed without additional information, the literature (as of 1993)
contained no detailed explanation.

Cattle

Humans

General symptoms of poisoning:

Mouth,
irritation of.

Notes on poisoning:

Mouth and throat
irritation, accompanied by pain and swelling, occurs upon chewing of plant
parts. The insoluble oxalates do not produce systemic poisoning in humans.
Washing or heating the rhizome can inactivate the oxalates. In northern Europe
the ground rhizome is used as flour for bread (Frohne and Pfander 1983, Lampe
and McCann 1985).